I don’t know the answer to your question but this is what I do know.

It’s only daytime slots which are severely restricted at HND. Late night and early morning (2300-0600) slots are readily available but not convenient for European airlines. (ANA’s HND-FRA service which departs after midnight is very popular. ANA’s new HND-VIE service departs at 0120. Both depart up to one hour later in winter.)

Until now daytime slots have been allocated in equal numbers to Japanese and foreign carriers per country. So 4 slots between France and Japan with 2 slots going to AF and 1 slot each to ANA and JL. Germany-Japan was also allocated 4 slots with 2 slots going to LH and 2 slots to ANA. If they follow this pattern Switzerland will never get a slot unless a Japanese carrier starts a direct service between Japan and Switzerland. On the other hand SAS is hoping to get a slot at HND though no Japanese airline has a direct flight to Scandinavia.

They recently allocated 12 slots to US carriers and will probably allocate the same number to Japanese carriers on Japan-US routes. They still have a similar number of additional daytime slots to allocate for the summer 2020 season but I have not been able to find any further information so far.